Fig. 6. Biological role of the coiled-coil motif. Western-blot analysis of cell extracts and virus pellets from cells transfected with the infectious clone pHFV13, the corresponding clone harboring the GagL171G mutation (pHFVGagL171G), pSG-Gag and pCgp9, detected by polyclonal anti-Gag antibodies. The virus titer from cells transfected with pHFV13, corresponding to 9x10⁴ FCFU ml^–1, was arbitrarily set at 100%. The L171G point mutation does not affect particle release but dramatically reduces infectivity of the corresponding virus by more than 90% (6.2x10³ FCFU ml^–1).